SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d3f46b941fa2e5d5da01f469552aea1866ba116e843ff79b777bbeecac08e78' 
  AND token = 'sitpmuGbOUlYgSvsdl5TVxMiBCzQ6DtQBCvYoGiaavM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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