SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '262774429e5c44db33796671e8117b27395a9d4d10f246678aab24cdefa132d8' 
  AND token = 'IgL7WNDN6JYQIx7PgAVf2h+MZ5yKJw+orVcAZ2jl3w0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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