SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce547d15984245addd5a3c3c37bd56080ab0295c41f7cac25947c6f728619fa4' 
  AND token = 'VEl7sarWcuBSVVN5/YO7ZLQjG0JTlKcL1+UlIpJI8jE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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