SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d37271e88a6adec7eae41e85821683eb6949f69dd1fc4a536aad83eab27325' 
  AND token = 'ft+N/9Tp0mmXQybhlldK0QrsMumtygCdV+7ZArlpahA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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