SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6de9e58ff742cc260d9888556a26f7975ac6b88970f9257ba43a09ccfd76f047' 
  AND token = 'bNI/72H5Orik5wSJ5FpG3mMwZMB6vScEivOa+5gMC3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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