SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4695c2f314446d788c982f811af47c4ffac0debbbaaaed70254d27541027b29d' 
  AND token = 'En/lepN2/+dyf+2IpCPXhTYcJsws0a8CAFcA5N+Q0XE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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