SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08a82a987d42ecfb2aa975afa3678c13b048bfdcb371cf677e17894419214506' 
  AND token = 'CFYJOD4SBMeqB4lEpnMFX0oEEtpvOotZ/eaRP+o3p24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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