SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '463ee398b479d00fa3fe597fb1f88f500ef9d6a1555e34bf9befcbf7a1abfb3f' 
  AND token = 'x6JpLmZeGSHoo1+brXwljdqCDJCsDmUFj9XUuKGo25c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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