SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7049cb09bce97920282bd915f9e4c3d7f3a487afde0fb83e363515902db9a34' 
  AND token = 'MUtvvUfDjAkJox2Nk3WlCjMJ2tbKTZQT9ZD8norhHtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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