SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a700d2a4e6dc8f1272e7790efc9298ce9a7a27450d6712f5fb47861709b50564' 
  AND token = 'DTBPDYa+gfZAZUNQg/LBzFbod2TXEu9VmghBK4t1ulY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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