SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e402fb6d17994af70b03ba91ae7f2af5e20655d66a827ffeee5be4080c48b88c' 
  AND token = 'w/Z0hhYonQXdFoTIK7rN8wDWwkj5csJ3td6aJeb2KYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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