SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86e24daf5a198f283f550302575966c52c4adb32d71864a676fd4285aeeb1c09' 
  AND token = '5towvbDNTAlLumUF2gQX3X+5hxDQjJvYeZZRMlRAfeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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