SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db2f8c2af7bbf7449682f41179d31d1f26a4461a8d8af04203c6782cd79b879' 
  AND token = '7ApNFQWHmz/Fg5qZZKoRQhGtQZET45Z+L0I3TOjclCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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