SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38ba7083a3d55b8c684c4574da609172d03dd0804c9e0c3df3e1754d43c44866' 
  AND token = 'Ya78t6NNfsKVBXcOJbUIJx8gcYn1yR1yLTpvHB/SuLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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