SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ad9639188b72d9bab605ab256884f2c3015390ea4d27f3fd1050b40eeecaf135' 
  AND token = 'XheVoqN8IFWLq7+BGu1sab4JP7vZf0yikAqt4nH96Oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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