SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71263a22054096e9e2f7b87ebd4325e3db5296cd41ff6c357400c14a74f0764a' 
  AND token = 'pLZnwPJTZsIE8gbnuAwWA4EweOHM26qpEizjmKrq/w8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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