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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '909e7f92d19cb01414f96a6edd1747f6bb21a1e7767888f9d5d7d2252c2fc7cb' 
  AND token = '9I8ORQkK9Zj65g/HEKkvmS+Imd8VeqAOZ9ks8A3RRF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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