SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d440e8b68dd03ad062dfa3a344cc49ba93fdbbff623aac1559655ccf725f23' 
  AND token = 'NPBThnXp/q04SHeMRKqKgYmydfvJtPCC0Dtv5aERwds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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