SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e5b778c209581eb093d53f245ae9972f456baeebb0a1dc11af2dc59ea34096b' 
  AND token = 'MqQdAvo5ZQjup8xVWT/T4J/LsCnkV1nLEd1IsK4LzfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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