SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d146fe4bcffd2d74b6a17b97517c003c3c1faed9e7ef335da246ff7595c85de' 
  AND token = 'P6vYYKyVb7hQ9aUAMESli23/yfAV7JHcGbxBMTVTwFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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