Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6aadb7daf4fdf29b669f970edbe3f4b7e8388f0e917f0c904a24437817e2cd3' 
  AND token = 'mVb9d4Yiz7bh2Fh+1uNZRpB3RvodaBhYTLuJ+vQId0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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