SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89af5bdf730f07a59d80d8fae926c3f6c3239ef240aff3708c099d7a30267753' 
  AND token = 'uX/iEyGg2hgRZXAM0jjLmdgkjcIVOhkKP6Yl27vhaec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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