SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a9ee7b42b45b7ec71cbdfdfc99aea7dbbe93b414c3306ab21250a67c3cd93ea' 
  AND token = 'HoeWWLSJrNTU4HoPREoP7QZqLjgCnC33CkA6Xefg28g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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