SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f1466f6a93b01f52ef2202bd63958eb41cf7501648ecd8603477c00fc6d0dcc' 
  AND token = 'oviRgXKtn6baY4UzGhuHt4zya0SCVEQRoBdFUVdrluA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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