SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67165232c0cda1089d6e5a48f186e70edbba2fd92ff9c4af7696e6393216e94b' 
  AND token = 'F/+wKfHooWYlLmi41To7ulSPbJoPnFpCro7DoBe1I38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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