SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7e76a8374f7b2e71de254503b78870a8aa99f02dc4045534cbd1cb7a482779c' 
  AND token = 'co9YIPwig/1Cuf2VMnNJqC0F5vYRsJY+Q6wPxq4xNus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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