SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ba228ec723f898e2872932e8121cb64ca90b4d2b7d6f4e9c8340e6683e9dbd' 
  AND token = 'i+ECPgLXzvg0/T+xhIjNtGR/ytpsJD4WANlWFGFKidU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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