SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2df3250e63b8d271538cca178db07a33ae281b7a5d4f38ad6fbd8382aa2cf8e4' 
  AND token = 'YlBP7OsmTNm9hmCRu/HUgedTr8kqisgejMWeuP/0xVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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