SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8cdacfe5857d29999ac5d65afa717287937546c9158f105b5f6637b6de0d0d82' 
  AND token = 'NB2qYagWlaBfr08Wc+Xnu7mnS4TV6zekqbQK6SFPKos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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