SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f73899859988292ea1e578943f128469e36b61e1b442471dbae09b40c9768552' 
  AND token = 'dcdBVZpXeBIasgYpr8H7eBbSOI6QCl0Jn2mnzBtZQ3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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