SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57d9805bff26704de04767bf1b612a17f440fec29780c769d32e97846ca740b6' 
  AND token = 'RQJPmQSywjn+9n8NTX8rqZm5RBpQPvivcd0z5tA3Has=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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