SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d635f3c9582278ba27f71e6c6d83d41ec1256d9ef9ffa7d8255a4051c9d5d39' 
  AND token = 'HTqGb3ihwiFvTCYWRQVV/cuX5YBdPaWN6jXxDv+TLsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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