SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd62d190bdb8c4222a6ca5accfb348fabdc90cb282c64d42fbd25ee0488b2d96c' 
  AND token = 'M1BmtBOtAVjb7TzUKxdOyURYuKIPv0NdqRVGzcwqtt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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