SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06ba63667b2f159e5c025e2f93b788e0d0609d65380a5e0d8e149380b725da64' 
  AND token = 'dF3hk5PQKX4Q7dP23JiHzsf+JFsi/FAYvK85liGf7xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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