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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd4e2173aaa0982990c6b89f3a8ac4ee4f6cfa5a1d0fc4602f6b09ca31a9eb1e' 
  AND token = 'qfMKlgOZ2iIiBGptyRuvd6qMw2eTy1Uc4QM8avT/9Ts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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