SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f6f815ae2af61320abeb5b41ea58fa51ecb15c58028261550b9902dba2fa967' 
  AND token = 'SQGbYPvTlVMrIM2bzlnWAi9V+u2XQSlVWtrQnWNSxbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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