SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adaff91881c35887fe761df8819379b0b74c816ef5d8730e42bb1f3ed7ac9f82' 
  AND token = 'DRxpupkGoGTRqnYsv/v3opQ83lr164dbFlCYQmo3VgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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