SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cf12e1a92829d0c5cdb4a8fd35f05b639b29b70362de961f14aba41c0709d1e' 
  AND token = 'FCPmRvZOviH0Kgc2Ffy1DeX7fDMbjpb3isMgUWyKpao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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