SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26292af53b15aa813bda4f190a635d056165a56b4db42342c180bf60d624424a' 
  AND token = 'MP6YZ8j3fBEIpsjwOLb8/c1dKPem5AbOGXad7iE/tUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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