SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd3a3c4cc255b2f5221b651c4ecfe72b9c1f42332c00db59a1883fdabf678f2' 
  AND token = 'xtmcPue0erpcHpTe6tOtI42MjC7cgHWcF/sw6VeSlV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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