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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a304449a7f2ab1f94c78c73bcb617b656a4368d03cfc9cfd71001dea4cf8f1d6' 
  AND token = '0ix3BC8LcFkDemSsFcBM1hqUwH90HJG4VEwpLbVM+6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}