SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4cb80477e811d4579fd1ff238ddb83e8d1b3005f48fd68486770e8c479ddc6d' 
  AND token = 'yt4fvvd+6DI+Wwy6nGjrnacmFm1wfoQ4TruW3hDyQk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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