SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8e37faafc2a89b8257cabef13ad5434c4c06691115c601aaea57436dd6ce14f0' 
  AND token = '1ncp00m2hkMG2LYev5Qqs4Ua910qq5COyQwsTsvfpOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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