SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5739564e06ca6bcd77d6353abf63a7194b96fa936d098827833f8c2ab626c9c3' 
  AND token = 'TtC2i2ShkG27XuUZhpTysDqXkYEwtZcn9S+hPTkJC78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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