SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ae3b8044812369a10c5da10323beace2c7a90802342ea8654dae5dccf999fac' 
  AND token = 'WtSYkBsCAQngZj1QX+tY/NbK7dPTIZ1UQIe/eLkxMBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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