SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fcfddb470fa843ee203152bf0b54a871bda920c86e3917c491b41c9ffdc51076' 
  AND token = 'SjgrcZJq17f2JT8EMIrbtba57tRBBpZ8Mzl8Kob7OwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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