SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0861a2793af00a41df7fb08a934f7d93f4ff5dd0e87e76c783995c3676f0eaf5' 
  AND token = 'H0FODyYfDuAfDZmLvnXHD/qlTp/fwcZGgkFL/KQJHXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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