SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53f388fb6a863815b41343f0d04fe9456479364d7c622879cc8df8411d18e3d8' 
  AND token = 'Fr2S3nxneC4o3/D745JSyYjGhpLhNsKd7yO9gAYFbWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}