SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36afa6eaf096233c86fa9255266c890e1562d195eef3078101ac4ce2b886c161' 
  AND token = 'VYPHQXgz100s1H1VkpciFVaNp0IFmPALIdtgxcjD6HY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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