SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82875021adddc6e10ddbb567fbdebdb7932fff0009fe1945ee9f5d7bbb675ca3' 
  AND token = 'FtFq5hVNdi0SZXOQRwDlIaHjnYbXJZFTReBir0rk3/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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