SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a08ee3e772223b14accb78a771f76d796bd6b812f27754a6bf3784ca86e6c54' 
  AND token = 'kSVqazscFUGJBfxL/YwOnF45gMO0Mvs41UYIWpR47A4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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