SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2975d4fff10d4524546edd7ab28a752da64cf6f033d7ad9ad851371bb93d91f5' 
  AND token = 'RPB06C6rvI9l+MMkwHsqYB39R1CAgGO+0NMTXrOR4SA=' 
  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"
    }
  }
}