SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '953923879ad6d1a32eedbf2565d5fc997069a482c6598f887b3438b3c9c8c4c1' 
  AND token = 'hFUThbHgZHu/eTQ0w4/xJg1jiCy4vHISSVCleJtCtkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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