SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c4adecab10f94749ca50ce756f32af9c9c43764c71bcf64af3b5014672ba729' 
  AND token = 'HlQ8hthFMPG3BFsiPwYgqhRBk8jH1i7qIzeWW7ZRB9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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