SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b3e308742246f41b2101f6ee3f63f710928c033e6640c694425d024cc442583' 
  AND token = 'iaemjbZXESrlLETTnBS/GThOJwXVXaiQlfRw52WqvQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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