SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '443cf8e454c022606509aa9ff4355b55dd3846fece24e3072ba08b88f04b13de' 
  AND token = 'TRd2IcZlVLTqQRugtwNSzJQomq/1W5LTqYhVCfv+Jks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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