SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '816d32b94b8a168f20599ca7a6a184cd50851d62ca67ef2cd6c15655b873832e' 
  AND token = 'dqDwEswYYI4eCPKQv6dB9+pDvDhh24PxVQ3T3yjjOpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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