SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dfa927755fb24dbcd60aa578a1fcc0d7f7080afdd628f91ba195999a3242248' 
  AND token = 'J+GcOrJK9H1V1OW7dCdes1gSe0XIjU2kEwo8YjduJ2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}