SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cb3ef1d884b675a2e8d2f5c09e86fea54c4d8817510fd4d4f9b1ca1b30edd6e' 
  AND token = '4YSyCKgLACN9jyu3ujCr1nXnjHh/snooRXs/2M4iNVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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