SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f7a8df21b14a20624dcccb270e5289ceef6364936db5734fada7b0acc1eb61f' 
  AND token = 'Ico1SnTsQW9iryWCx3xGRvrqcF1iDHD7nWesRqsOhdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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