SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27d60ead176fb3bbd6381f2a63bbbfac41d97945110a655ec895c1e68fe829b7' 
  AND token = '8FijAwWiiqGTD1gneRk0MIcq9gWgOxzEBHVivxqqKmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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