SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25df3ce6b2cd3641f2aa5de5bdb662e46c8dad163ce0897d7eb989dd2a660808' 
  AND token = 'NUeUwkyJaZTSEVWEfTDGAkRv405HL4znubm9MaKYZB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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