SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23623f0cfe68816abda2f7b96b9cb8ac0565fd250ca0648e51e8f100945db685' 
  AND token = 'DOVGR68CL1SvgQ2j/8jnKOopxnK9IzkgM/KoCttVOaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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