SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '394cb2968c219f79e3959d5cd5aacb762a2397cd5272f4825cc62277ab44c581' 
  AND token = 'HAYrPw/dX5r40tFXGMVdSt+74Kmx2Cr87qYIT3ZDAb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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