SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '697ef2a9ddd8e09ff1af9728dac76638fc6df703f7edd40ace7ee2a848ef06b4' 
  AND token = 'SGrwjW2sGyBfXhmAQjIpxsVWjGduKQErMpT0p9eZ2ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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